a. Field of the Disclosure
The instant disclosure relates generally to a deflectable catheter shaft, and particularly to a catheter shaft with compression resistance coils.
b. Background Art
Electrophysiology catheters are used in a variety of diagnostic, therapeutic, mapping, and ablation procedures to diagnose and/or correct conditions such as atrial arrhythmias, including, for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmias can create a variety of conditions including irregular heart rates, loss of synchronous atrioventricular contractions, and stasis of blood flow a chamber of a heart, all of which can lead to a variety of symptomatic and asymptomatic ailments and even death.
Typically, a catheter is deployed and manipulated through a patient's vasculature to the intended site—for example, a site within a patient's heart or a chamber or vein thereof. The catheter carries one or more electrodes that can be used for cardiac mapping or diagnosis, ablation and/or other therapy delivery modes, or both, for example. Once at the intended site, treatment can include, for example, radio frequency (RF) ablation, cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound-based ablation, microwave ablation, and/or other ablation treatments. The catheter imparts ablative energy to cardiac tissue to create one or more lesions in the cardiac tissue and oftentimes a contiguous or linear and transmural lesion. This lesion disrupts undesirable cardiac activation pathways and thereby limits, corrals, or prevents errant conduction signals that can form the basis for arrhythmias.
To position a catheter within the body at a desired site, some type of navigation must be used, such as using mechanical steering features incorporated into the catheter (or an introducer sheath). In some examples, medical personnel may manually manipulate and/or operate the catheter using the mechanical steering features.
To facilitate the advancement of catheters through a patient's vasculature, the proximal end of the catheter can be manipulated to guide the catheter through vessels and heart chambers. The simultaneous application of torque at the proximal end of the catheter and the ability to selectively deflect the distal tip of the catheter in a desired direction can permit medical personnel to adjust the direction of advancement of the distal end of the catheter and to position the distal portion of the catheter during an electrophysiological procedure. The distal tip can be deflected by one or more pull wires attached at the distal end of the catheter that extends proximally to a control handle, for example, that controls the application of tension on the pull wire or pull wires.
Two of the mechanical considerations for a catheter shaft are that it transmit torque and resist compression during use. With respect to transmitting torque, medical personnel normally navigate the distal end of the catheter to a desired location in part by manipulating a handle disposed at the proximal end of the catheter shaft, or by rolling the proximal portion of the catheter shaft about its longitudinal axis with their fingers. Substantial frictional forces sometimes resist transmission of torque down the length of the catheter. With respect to resisting compression during use, catheter shafts may include compression coils that may comprise a plurality of stacked coils, such that the catheter shaft may be laterally deflected or curved while resisting longitudinal compression and the concomitant problems that such longitudinal compression may cause.
The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.